-er -ic b-u bbb bbc bbe bbi bbm bbr bbu bcb bcc bce bci bcm bcr bcu be- beb bec bee bei bem ber beu bi- bib bic bie bii bim bir biu bmb bmc bme bmi bmm bmr bmu brb bre bri brm brr bru bub buc bue bui bum bur buu c-- cbb cbc cbe cbi cbm cbr cbu ccb ccc cce cci ccm ccr ccu ce- ceb cec cee cei cem cer ceu ci- cib cic cie cii cim cir ciu cmb cmc cme cmi cmm cmr cmu crb crc cre cri crm crr cru cub cuc cue cui cum cur cuu ebb ebc ebe ebi ebm ebr ebu ec- ecb ecc ece eci ecm ecr ecu eeb eec eee eem eer eib eic eie eii eim eir eiu em- emb emc eme emi emm emr emu erb erc ere eri erm err eru eu- eub euc eue eui eur ibb ibc ibe ibi ibm ibr ibu icb icc ice ici icm icr icu ie- iec iee iei iem ier iib iic iie iii iim iir iiu im- imb imc ime imi imm imu ir- irb irc ire iri irm irr iru iu- iub iuc iue iui ium iur m-r mbb mbc mbe mbi mbm mbr mbu mc- mcb mcc mce mci mcm mcr mcu meb mec mee mei mem mer meu mi- mib mic mie mii mim mir miu mmb mmc mme mmi mmm mmr mmu mrb mrc mre mri mrm mrr mru mub muc mue mui mum mur muu rbb rbc rbe rbi rbm rbr rbu rcb rcc rce rci rcm rcr rcu re- reb rec ree rei rem rer reu rib ric rie rii rim rir rmb rmc rme rmi rmm rmr rrb rrc rri rrm rrr rru rub ruc rue rui rum rur ruu ubb ubc ube ubi ubr ubu ucb ucc uce uci ucm ucr ucu ueb uec uee uei uem uer uib uic uie uii uim uir uiu um- umb umc ume umi umm umr umu ur- urb urc ure uri urm urr uru uuc uue uum uur uuu